Programmable Superconducting AC Machine (PSAM)

可编程超导交流电机 (PSAM)

基本信息

批准号：
EP/J500756/1
负责人：
Timothy Coombs
金额：
$ 23.44万
依托单位：
University of Cambridge
依托单位国家：
英国
项目类别：
Research Grant
财政年份：
2011
资助国家：
英国
起止时间：
2011 至无数据
项目状态：
已结题

来源：
https://gtr.ukri.org/projects?ref=EP%2FJ500756%2F1
关键词：
Programmable Superconducting AC Machine PSAM

项目摘要

The magnetic circuit design is fundamental to the success of the final solution. To reduce the risk of developing the superconducting enabling technology the demonstrator design will be based on using standard magnetic steels and geometry architectures to achieve a doubling of the air-gap flux density. Some magnetic materials characteristics are known at cryogenic temperatures but the availability of particular key data such as ac electrical, Curie point and saturation flux density is very limited. The University of Cambridge will initially support the project by directing the selection of the most suitable conventional magnetic steel for use in the demonstrator, along with guidance on unidentified material data for use in modelling the demonstrator performance. The optimisation of magnetic materials is key to enabling the full benefits of a totally superconducting machine to be realised. For the programmable magnets the main challenges are the optimisation of the Currie and saturation point of the materials and how this impacts the preferred charging cycle and the actual magnet operating temperature. This in turn directs the preferred location of the magnetising jig. A significant challenge to an optimum magnetic material has been identified as the quality of the manufacturing process, heating treatment and the chemical composition of the material. The chemical composition affects the Curie temperature and the charge carrier density. The heat treatment profile affects the diffusion of the ions into the oxygen lattices and the manufacturing method affects the homogeneity and uniformity of the material. For the superconducting stator the main challenges are maximising the flux linking the superconducting coil by creating a low reluctance path. The prevention of flux leakage that will reduce both the flux linkage and the operating point of the superconductor can be achieved using a high permeability material. Although Proposal original proforma documentPage 3 of 9 Date printed: 16/02/2011 09:39:22TS/J001082/1 Date saved: 15/02/2011 15:49:48extremely limited mechanical, thermal and magnetic material property data currently exists at the cryogenic temperature of interest 25K, it has been observed that the use of iron at cryogenic temperatures has yielded benefits for dc superconducting magnets. However, for cryogenic ac magnetic systems, this convention needs to be re-visited. The ability of magnetic material to provide a low reluctance path whilst providing very low loss densities will need further consideration. There is a significant risk that conventional steels at cryogenic temperatures will incur significant eddy current losses (due to the increased electrical conductivity) and higher hysteresis losses leading to an impractical cryogenic solution. The loss density, thermal and magnetic performance as a function of frequency of a range of magnetic steels needs to be understood. Work should also consider alternative non-conventional room temperature materials that may also exhibit enhanced permeabilities at cryogenic temperatures. This work by its nature must also consider the long-term stability of the material under thermal and mechanical stresses. It is likely that the result of this study may lead to different machine constructions such as the location of the permanent magnet fixture jig, the cooling circuit construction and the overall machine topology such as an inside machine to be considered. This work will used to guide the full-scale outline design.

磁路设计是最终解决方案成功的基础。为了降低开发超导使能技术的风险，演示器设计将基于使用标准磁钢和几何结构，以实现气隙磁通密度加倍。一些磁性材料的特性在低温下是已知的，但特定关键数据（例如交流电、居里点和饱和磁通密度）的可用性非常有限。剑桥大学最初将支持该项目，指导选择最适合演示器使用的传统磁钢，并指导用于演示器性能建模的未识别材料数据。磁性材料的优化是实现全超导机器全部优势的关键。对于可编程磁体，主要挑战是材料的居里和饱和点的优化以及这如何影响首选充电周期和实际磁体工作温度。这反过来又指导磁化夹具的优选位置。最佳磁性材料面临的重大挑战是制造工艺、热处理和材料化学成分的质量。化学成分影响居里温度和载流子密度。热处理曲线影响离子扩散到氧晶格中，制造方法影响材料的均匀性和均匀性。对于超导定子来说，主要挑战是通过创建低磁阻路径来最大化链接超导线圈的磁通。使用高导磁率材料可以防止磁通泄漏，从而降低超导体的磁链和工作点。尽管提案原始形式文件第 3 页（共 9 页）打印日期： 16/02/2011 09:39:22TS/J001082/1 保存日期： 15/02/2011 15:49:48 目前存在的机械、热和磁性材料属性数据极为有限感兴趣的低温温度为 25K，据观察，在低温温度下使用铁已经产生了好处直流超导磁体。然而，对于低温交流磁系统，需要重新审视这一惯例。磁性材料提供低磁阻路径同时提供非常低的损耗密度的能力将需要进一步考虑。传统钢在低温下存在显着的风险，即会产生显着的涡流损耗（由于电导率增加）和更高的磁滞损耗，从而导致低温解决方案不切实际。需要了解一系列磁钢的损耗密度、热性能和磁性能作为频率的函数。工作还应考虑替代的非常规室温材料，这些材料在低温下也可能表现出增强的渗透性。这项工作本质上还必须考虑材料在热应力和机械应力下的长期稳定性。这项研究的结果可能会导致不同的机器结构，例如永磁体固定夹具的位置、冷却回路结构和整体机器拓扑（例如要考虑的内部机器）。这项工作将用于指导全面的轮廓设计。